Cationic polymers have been used widely in fields like cosmetics and personal care, water treatment, papermaking and oil chemistry.
Cationic conditioners are the key component of the shampoo. Cationic polymers are the main kind of cationic conditioner which improve conditioning, combability and provide softness and smoothness for hair. Because the electrostatic interaction between positive charged cationic polymers and the negative charged hair surface, cationic polymers can adsorb on the hair surface and improve the combability and ameliorate electrostatic charging of the hair. On the other hand, when diluting the shampoo, complex coacervates will be formed between the cationic polymers and anionic surfactants. These complex coacervates can help silicone oil and other functional ingredients to deposit on the hair surface to soften, smooth and repair the hair. Molecular weight and charge density of cationic polymer are key factors which influence the adsorption of cationic polymer and deposition of silicone oil on hair surface. The previous works show that cationic polymer with smaller molecular weight and higher charge density can adsorb on hair more quickly and the adsorbed amount is higher, whereas cationic polymer with larger molecular weight and moderate charge density favors deposition of silicone oil on hair. Cationic cellulose derivatives and cationic guar gum are two kind of main commercial cationic polymeric conditioner in shampoo. However, these cationic nature polymers are expensive.
In addition, they have some drawbacks due to limitation of molecular structure of nature polymer. For example, the solution of cationic guar gum is not clear so that it cannot be used in transparent shampoo formulation. Therefore, development of cationic polymeric conditioners with low price as well as excellent function is still a challenge.
Arabinoxylans are the main hemicelluloses of cereal cell walls and can be widely found in cereal bran and endosperm. The basic structure of arabinoxylans consists of a linear (1→4)-β-D-linked xylopyranosyl (Xylp) backbone, with α-L-arabinofuranosyl (Araf) side units attached to O-3 and/or O-2 of backbone Xylp units. In addition, a few ferulic acid groups may be attached to the Araf units. The type of substitution of arabinoxylans, whether consisting of single Araf branches or larger and more structurally complicated branches, varies depending on the source of arabinoxylans. The molecular weight of cereal arabinoxylans varies from tens of thousands to several millions (g/mol) depending on the source of arabinoxylans. Due to the advantages like wide accessible raw material, diversity structure, inexpensive, biocompatible, nontoxic, film building, antioxidation and bioactive of cereal arabinoxylans, they have important potential to be used in the cosmetics, pharmaceutical, and food industry.
U.S. Pat. No. 6,388,069 B1 disclosed a method of extracting arabinoxylan from corn fiber and the methods of preparing novel arabinoxylan esters and ethers. However, the invention does not involve the synthesis, hydrophobic modification and application of cationic cereal arabinoxylans.